Jabber

Jabber allows you to send short messages to your coworkers allowing them to answer when they are available. Some of its best aspects are allowing conversations to stop and start as needed, to take place in meetings where you wouldn’t ordinarily be able to speak to someone else at the same time, to take place while you are performing other tasks, or to allow for a more conversational and less formal means of communication than email. In addition, Jabber can let you easily see if someone is available, in a meeting, or otherwise not available.